TI TL1431CKTPR

TL1431
PRECISION PROGRAMMABLE REFERENCE
SLVS062F – DECEMBER 1991 – REVISED JANUARY 2000
D
D
D
D
D
D
D PACKAGE
(TOP VIEW)
0.4% Initial Voltage Tolerance
0.2-Ω Typical Output Impedance
Fast Turnon . . . 500 ns
Sink Current Capability . . . 1 mA to 100 mA
Low Reference Current (REF)
Adjustable Output Voltage . . . VI(ref) to 36 V
CATHODE
ANODE
ANODE
NC
1
8
2
7
3
6
4
5
REF
ANODE
ANODE
NC
NC – No internal connection
ANODE terminals are connected internally.
description
The TL1431 is a precision programmable
reference with specified thermal stability over
automotive,
commercial,
and
military
temperature ranges. The output voltage can be
set to any value between VI(ref) (approximately
2.5 V) and 36 V with two external resistors (see
Figure 16). This device has a typical output
impedance of 0.2 Ω. Active output circuitry
provides a very sharp turnon characteristic,
making the device an excellent replacement for
zener diodes and other types of references in
applications such as onboard regulation,
adjustable power supplies, and switching power
supplies.
CATHODE
ANODE
REF
KTP PACKAGE
(TOP VIEW)
CATHODE
ANODE
ANODE
REF
The ANODE terminal is in electrical contact with the
mounting base.
FK PACKAGE
(TOP VIEW)
NC
CATHODE
NC
REF
NC
The TL1431C is characterized for operation over
the commercial temperature range of 0°C to
70°C. The TL1431Q is characterized for
operation over the full automotive temperature
range of –40°C to 125°C. The TL1431M is
characterized for operation over the full military
temperature range of –55°C to 125°C.
LP PACKAGE
(TOP VIEW)
JG PACKAGE
(TOP VIEW)
CATHODE
NC
NC
NC
1
8
2
7
3
6
4
5
REF
NC
ANODE
NC
NC
NC
NC
NC
NC
3 2 1 20 19
18
5
17
6
16
7
15
8
14
9 10 11 12 13
NC
NC
NC
ANODE
NC
NC
NC
NC
NC
NC
NC – No internal connection
4
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Copyright  2000, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
On products compliant to MIL-PRF-38535, all parameters are tested
unless otherwise noted. On all other products, production
processing does not necessarily include testing of all parameters.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
1
TL1431
PRECISION PROGRAMMABLE REFERENCE
SLVS062F – DECEMBER 1991 – REVISED JANUARY 2000
AVAILABLE OPTIONS
PACKAGED DEVICES
TA
SMALL
OUTLINE
(D)
PLASTIC
FLANGE
MOUNTED
(KTP)
TO-226AA
(LP)
CHIP
CARRIER
(FK)
CERAMIC
DIP
(JG)
–
0°C to 70°C
TL1431CD
TL1431CKTPR
TL1431CLP
–
–40°C to 125°C
TL1431QD
–
TL1431QLP
–
–
–55°C to 125°C
–
–
–
TL1431MFK
TL1431MJG
CHIP
FORM
(Y)
TL1431Y
The D and LP packages are available taped and reeled. The KTP package is only available taped and reeled. Add the suffix R
to the device type (e.g., TL1431CDR). Chip forms are tested at 25°C.
logic symbol
REF
ANODE
CATHODE
functional block diagram
CATHODE
REF
+
–
Vref
ANODE
2
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TL1431
PRECISION PROGRAMMABLE REFERENCE
SLVS062F – DECEMBER 1991 – REVISED JANUARY 2000
equivalent schematic†
CATHODE
1
800 Ω
800 Ω
REF
8
20 pF
150 Ω
3.28 kΩ
4 kΩ
10 kΩ
2.4 kΩ
7.2 kΩ
20 pF
1 kΩ
800 Ω
ANODE
2,3,6,7
† All component values are nominal.
Pin numbers shown are for the D package.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
3
TL1431
PRECISION PROGRAMMABLE REFERENCE
SLVS062F – DECEMBER 1991 – REVISED JANUARY 2000
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)†
Cathode voltage,VKA (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 V
Continuous cathode current range, IKA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –100 mA to 150 mA
Reference input current range, II(ref) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –50 µA to 10 mA
Package thermal impedance, θJA (see Notes 2 and 3): D package . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97°C/W
KTP package . . . . . . . . . . . . . . . . . . . . . . . . . 28°C/W
LP package . . . . . . . . . . . . . . . . . . . . . . . . . . 156°C/W
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°C
Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –65°C to 150°C
† Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied.
Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTES: 1. All voltage values are with respect to ANODE unless otherwise noted.
2. Maximum power dissipation is a function of TJ(max), θJA, and TA. The maximum allowable power dissipation at any allowable ambient
temperature is PD = (TJ(max) – TA)/θJA. Operating at the absolute maximum TJ of 150°C can impact reliability.
3. The package thermal impedance is calculated in accordance with JESD 51.
POWER DISSIPATION RATING TABLE – FREE-AIR TEMPERATURE
PACKAGE
TA = 25°C
POWER RATING
DERATING
FACTOR ABOVE
TA = 25°C
TA = 70°C
POWER RATING
TA = 85°C
POWER RATING
TA = 125°C
POWER RATING
FK
1375 mW
11.0 mW/°C
880 mW
715 mW
275 mW
JG
1050 mW
8.4 mW/°C
672 mW
546 mW
210 mW
recommended operating conditions
VKA
IKA
TA
4
MIN
MAX
VI(ref)
1
36
V
100
mA
TL1431C
0
70
TL1431Q
–40
125
TL1431M
–55
125
Cathode voltage
Cathode current
Operating free-air temperature
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
UNIT
°C
TL1431
PRECISION PROGRAMMABLE REFERENCE
SLVS062F – DECEMBER 1991 – REVISED JANUARY 2000
electrical characteristics at specified free-air temperature, IKA = 10 mA (unless otherwise noted)
PARAMETER
TEST CONDITIONS
TA†
TEST
CIRCUIT
25°C
TL1431C
MIN
TYP
MAX
2490
2500
2510
UNIT
VI(ref)
Reference
input voltage
VKA = VI(ref)
VI(dev)
Deviation of reference input
voltage over full temperature
range‡
VKA = VI(ref)
Full
range
Figure 1
4
20
mV
DVI(ref)
DVKA
Ratio of change in reference
input voltage to the change in
cathode voltage
∆VKA = 3 V to 36 V
Full
range
Figure 2
–1.1
–2
mV/V
Reference
input current
1.5
2.5
II(ref)
R1 = 10 kΩ,
R2 = ∞
Full
range
II(dev)
Deviation of reference input
current over full temperature
range‡
R1 = 10 kΩ,
R2 = ∞
Full
range
Figure 2
0.2
1.2
µA
Minimum cathode current for
regulation
VKA = VI(ref) to 36 V
25°C
Figure 1
0.45
1
mA
Off state
Off-state
cathode current
0.18
0.5
Ioff
VKA = 36 V,
|zKA|
Output impedance§
VKA = VI(ref), f ≤ 1 kHz,
IKA = 1 mA to 100 mA
Full
range
Figure 1
2480
25°C
Figure 2
Full
range
Figure 3
25°C
Figure 1
µA
3
25°C
VI(ref) = 0
mV
2520
µA
2
0.2
Ω
0.4
† Full range is 0°C to 70°C for C-suffix devices.
‡ The deviation parameters VI(dev) and II(dev) are defined as the differences between the maximum and minimum values obtained over the rated
is defined as:
temperature range. The average full-range temperature coefficient of the reference input voltage a V
ǒ
Ǔ
Ť Ťǒ Ǔ
V
aV
I(ref)
ppm
°C
+
V
I(dev)
at 25 C
I(ref)
°
I(ref)
106
Max VI(ref)
DTA
VI(dev)
where:
∆TA is the rated operating temperature range of the device.
Min VI(ref)
∆TA
aV
I(ref)
is positive or negative depending on whether minimum VI(ref) or maximum VI(ref), respectively, occurs at the lower temperature.
Ť Ť + DD
§ The output impedance is defined as: z
KA
V KA
IKA
ǒ Ǔ
When the device is operating with two external resistors (see Figure 2), the total dynamic impedance of the circuit is given by: |z′|
Ť Ť )
which is approximately equal to z KA
1
+ DDVI ,
R1 .
R2
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
5
TL1431
PRECISION PROGRAMMABLE REFERENCE
SLVS062F – DECEMBER 1991 – REVISED JANUARY 2000
electrical characteristics at specified free-air temperature, IKA = 10 mA (unless otherwise noted)
PARAMETER
TEST CONDITIONS
TA†
TL1431Q
TEST
CIRCUIT
25°C
TL1431M
MIN
TYP
MAX
MIN
TYP
MAX
2490
2500
2510
2475
2500
2540
2530
2460
UNIT
VI(ref)
Reference
input voltage
VKA = VI(ref)
VI(dev)
Deviation of
reference input
voltage over full
temperature range‡
VKA = VI(ref)
Full
range
Figure 1
17
55
17
55*
mV
DVI(ref)
DVKA
Ratio of change in
reference input
voltage to the
change in cathode
voltage
∆VKA = 3 V to 36 V
Full
range
Figure 2
–1.1
–2
–1.1
–2
mV/V
1.5
2.5
1.5
2.5
II(ref)
Reference
input current
R1 = 10 kΩ,
R2 = ∞
Full
range
II(dev)
Deviation of
reference input
current over full
temperature range‡
R1 = 10 kΩ,
R2 = ∞
Full
range
Figure 2
0.5
2
0.5
3*
µA
Minimum
cathode current
for regulation
VKA = VI(ref) to 36 V
25°C
Figure 1
0.45
1
0.45
1
mA
Off-state
Off
state
cathode current
0.18
0.5
0.18
0.5
Ioff
VKA = 36 V,
|zKA|
Output impedance§
VKA = VI(ref), f ≤ 1 kHz,
IKA = 1 mA to 100 mA
Full
range
Figure 1
2470
25°C
Figure 2
25°C
VI(ref) = 0
Full
range
Figure 3
25°C
Figure 1
4
µA
5
2
0.2
mV
2550
µA
2
0.4
0.2
Ω
0.4
*On products compliant to MIL-PRF-38535, this parameter is not production tested.
† Full range is –40°C to 125°C for Q-suffix devices, and –55°C to 125°C for M-suffix devices.
‡ The deviation parameters VI(dev) and II(dev) are defined as the differences between the maximum and minimum values obtained over the rated
temperature range. The average full-range temperature coefficient of the reference input voltage a V
is defined as:
ǒ
Ǔ
Ť Ťǒ Ǔ
V
aV
I(ref)
ppm
°C
+
V
I(dev)
at 25 C
I(ref)
°
I(ref)
106
Max VI(ref)
DTA
VI(dev)
where:
∆TA is the rated operating temperature range of the device.
Min VI(ref)
∆TA
aV
I(ref)
is positive or negative depending on whether minimum VI(ref) or maximum VI(ref), respectively, occurs at the lower temperature.
Ť Ť + DD
§ The output impedance is defined as: z
KA
V KA
IKA
ǒ Ǔ
When the device is operating with two external resistors (see Figure 2), the total dynamic impedance of the circuit is given by: |z′|
Ť Ť )
which is approximately equal to z KA
6
1
R1 .
R2
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
+ DDVI ,
TL1431
PRECISION PROGRAMMABLE REFERENCE
SLVS062F – DECEMBER 1991 – REVISED JANUARY 2000
electrical characteristics at IKA = 10 mA, TA = 25°C
PARAMETER
TEST CONDITIONS
TL1431Y
TEST
CIRCUIT
MIN
TYP
MAX
2490
2500
2510
UNIT
VI(ref)
Reference input voltage
VKA = VI(ref)
Figure 1
DVI(ref)
DVKA
Ratio of change
g in reference input voltage
g
to the change in cathode voltage
∆VKA = 3 V to 36 V
Figure 2
–1.1
11
–2
2
mV/V
II(ref)
IKAmin
Reference input current
R1 = 10 kΩ,
Figure 2
1.44
2.5
µA
Minimum cathode current for regulation
0.45
1
mA
Off-state cathode current
VKA = VI(ref) to 36 V
VKA = 36 V,
Vref = 0
Figure 1
Ioff
Figure 3
0.18
0.5
µA
Figure 1
0.2
0.4
Ω
VKA = VI(ref), f ≤ 1 kHz,
IKA = 1 mA to 100 mA
Output impedance†
|zKA|
† The output impedance is defined as: |z′|
R2 = ∞
+ DDVI
Ť Ť + DD
ǒ Ǔ
When the device is operating with two external resistors (see Figure 2), the total dynamic impedance of the circuit is given by: z KA
Ť Ť )
which is approximately equal to z KA
Ť Ťǒ Ǔ ǒ Ǔ
1
mV
V KA
,
IKA
R1 .
R2
PARAMETER MEASUREMENT INFORMATION
V
aV
I(ref)
ppm
°C
+
V
I(dev)
at 25 C
I(ref)
°
106
Max VI(ref)
DTA
VI(dev)
where:
∆TA is the rated operating temperature range of the device.
Min VI(ref)
∆TA
VKA
Input
VKA
Input
IKA
IKA
R1
VI(ref)
R2
Figure 1. Test Circuit for V(KA) = Vref
POST OFFICE BOX 655303
II(ref)
VI(ref)
V KA
ǒ Ǔ
+ VI(ref) 1 ) R1
) II(ref)
R2
R1
Figure 2. Test Circuit for V(KA) > Vref
• DALLAS, TEXAS 75265
7
TL1431
PRECISION PROGRAMMABLE REFERENCE
SLVS062F – DECEMBER 1991 – REVISED JANUARY 2000
PARAMETER MEASUREMENT INFORMATION
VKA
Input
Ioff
Figure 3. Test Circuit for Ioff
TYPICAL CHARACTERISTICS
Table of Graphs
FIGURE
Reference voltage vs Free-air temperature
4
Reference current vs Free-air temperature
5
Cathode current vs Cathode voltage
6, 7
Off-state cathode current vs Free-air temperature
8
8
Ratio of delta reference voltage to delta cathode voltage vs Free-air temperature
9
Equivalent input-noise voltage vs Frequency
10
Equivalent input-noise voltage over a 10-second period
11
Small-signal voltage amplification vs Frequency
12
Reference impedance vs Frequency
13
Pulse response
14
Stability boundary conditions
15
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TL1431
PRECISION PROGRAMMABLE REFERENCE
SLVS062F – DECEMBER 1991 – REVISED JANUARY 2000
TYPICAL CHARACTERISTICS†
REFERENCE VOLTAGE
vs
FREE-AIR TEMPERATURE
REFERENCE CURRENT
vs
FREE-AIR TEMPERATURE
2.52
2.5
IKA = 10 mA
R1 = 10 kΩ
R2 = ∞
I I(ref) – Reference Current – µ A
VI(ref) – Reference Voltage – V
VI(ref) = VKA
IKA = 10 mA
2.51
2.5
2.49
2.48
– 50
– 25
0
25
50
75
100
2
1.5
1
0.5
0
– 50
125
– 25
TA – Free-Air Temperature – °C
0
25
50
75
100
TA – Free-Air Temperature – °C
Figure 4
Figure 5
CATHODE CURRENT
vs
CATHODE VOLTAGE
CATHODE CURRENT
vs
CATHODE VOLTAGE
800
150
VKA = VI(ref)
TA = 25°C
VKA = VI(ref)
TA = 25°C
600
I KA – Cathode Current – µ A
I KA – Cathode Current – mA
100
50
0
– 50
– 100
– 150
–3
125
–2
–1
0
1
2
3
400
200
0
– 200
–2
–1
0
1
2
3
4
VKA – Cathode Voltage – V
VKA – Cathode Voltage – V
Figure 6
Figure 7
† Data at high and low temperatures are applicable only within the recommended operating free-air temperature ranges of the various devices.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
9
TL1431
PRECISION PROGRAMMABLE REFERENCE
SLVS062F – DECEMBER 1991 – REVISED JANUARY 2000
TYPICAL CHARACTERISTICS†
RATIO OF DELTA REFERENCE VOLTAGE TO
DELTA CATHODE VOLTAGE
vs
FREE-AIR TEMPERATURE
OFF-STATE CATHODE CURRENT
vs
FREE-AIR TEMPERATURE
0.35
–0.85
VKA = 3 V to 36 V
VKA = 36 V
VI(ref) = 0
–0.95
0.3
∆V I(ref) /∆V KA – mV/V
I KA(off) – Off-State Cathode Current – µ A
0.4
0.25
0.2
0.15
–1.05
–1.15
–1.25
0.1
–1.35
0.05
0
–50
– 25
0
25
50
75
100
–1.45
–50
125
– 25
TA – Free-Air Temperature – °C
0
25
50
75
100
125
TA – Free-Air Temperature – °C
Figure 8
Figure 9
EQUIVALENT INPUT-NOISE VOLTAGE
vs
FREQUENCY
260
Hz
IO = 10 mA
TA = 25°C
Vn – Equivalent Input Noise Voltage – nV/
240
220
200
180
160
140
120
100
10
100
1k
10 k
100 k
f – Frequency – Hz
Figure 10
† Data at high and low temperatures are applicable only within the recommended operating free-air temperature ranges of the various devices.
10
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TL1431
PRECISION PROGRAMMABLE REFERENCE
SLVS062F – DECEMBER 1991 – REVISED JANUARY 2000
TYPICAL CHARACTERISTICS
EQUIVALENT INPUT-NOISE VOLTAGE
OVER A 10-SECOND PERIOD
6
Vn – Equivalent Input Noise Voltage – µV
5
4
3
2
1
0
–1
–2
–3
–4
f = 0.1 to 10 Hz
IKA = 10 mA
TA = 25°C
–5
–6
0
2
4
6
8
10
t – Time – s
19.1 V
1 kΩ
910 Ω
2000 µF
VCC
VCC
500 µF
TL1431
(DUT)
+
TLE2027
AV = 10 V/mV
–
16 Ω
820 Ω
16 Ω
1 µF
16 Ω
+
TLE2027
–
2.2 µF
1 µF
160 kΩ
33 kΩ
AV = 2 V/V
0.1 µF
CRO 1 MΩ
33 kΩ
VEE
VEE
TEST CIRCUIT FOR 0.1-Hz TO 10-Hz EQUIVALENT INPUT-NOISE VOLTAGE
Figure 11
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
11
TL1431
PRECISION PROGRAMMABLE REFERENCE
SLVS062F – DECEMBER 1991 – REVISED JANUARY 2000
TYPICAL CHARACTERISTICS
SMALL-SIGNAL VOLTAGE AMPLIFICATION
vs
FREQUENCY
AV – Small-Signal Voltage Amplification – dB
60
IKA = 10 mA
TA = 25°C
Output
I(K)
50
15 kΩ
230 Ω
9 µF
40
+
30
8.25 kΩ
–
20
GND
10
0
1k
TEST CIRCUIT FOR VOLTAGE AMPLIFICATION
10 k
100 k
1M
10 M
f – Frequency – Hz
Figure 12
REFERENCE IMPEDANCE
vs
FREQUENCY
100
|zka
O
|z KA| – Reference Impedance – Ω
IKA = 1 mA to 100 mA
TA = 25°C
1 kΩ
Output
I(K)
10
50 Ω
–
+
1
GND
TEST CIRCUIT FOR REFERENCE IMPEDANCE
0.1
1k
10 k
100 k
1M
10 M
f – Frequency – Hz
Figure 13
12
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TL1431
PRECISION PROGRAMMABLE REFERENCE
SLVS062F – DECEMBER 1991 – REVISED JANUARY 2000
TYPICAL CHARACTERISTICS
PULSE RESPONSE
6
TA = 25°C
220 Ω
VI
Input
Output
Input and Output Voltages – V
5
4
Pulse
Generator
f = 100 kHz
3
Output
50 Ω
2
GND
1
TEST CIRCUIT FOR PULSE RESPONSE
0
0
1
5
2
3
4
t – Time – µs
6
7
Figure 14
150 Ω
STABILITY BOUNDARY CONDITIONS†
100
I KA – Cathode Current – mA
90
80
A-VKA = VI(ref)
B-VKA = 5 V
C-VKA = 10 V
D-VKA = 15 V
IKA
VI
+
IKA = 10 mA
TA = 25°C
CL
VBATT
–
70
Stable
60
Stable
B
C
TEST CIRCUIT FOR CURVE A
50
40
30
A
R1 =
10 kΩ
D
IKA
150 Ω
20
CL
10
VI
+
0
0.001
0.01
0.1
1
10
VBATT
R2
–
CL – Load Capacitance – µF
† The areas under the curves represent conditions that may cause the
device to oscillate. For curves B, C, and D, R2 and V+ are adjusted to
establish the initial VKA and IKA conditions with CL = 0. VBATT and CL
are then adjusted to determine the ranges of stability.
TEST CIRCUIT FOR CURVES B, C, AND D
Figure 15
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
13
TL1431
PRECISION PROGRAMMABLE REFERENCE
SLVS062F – DECEMBER 1991 – REVISED JANUARY 2000
APPLICATION INFORMATION
Table of Application Circuits
APPLICATION
FIGURE
Shunt regulator
16
Single-supply comparator with temperature-compensated threshold
17
Precision high-current series regulator
18
Output control of a three-terminal fixed regulator
19
Higher-current shunt regulator
20
Crowbar
21
Precision 5-V, 1.5-A, 0.5% regulator
22
5-V precision regulator
23
PWM converter with 0.5% reference
24
Voltage monitor
25
Delay timer
26
Precision current limiter
27
Precision constant-current sink
28
R
V(BATT)
V(BATT)
VO
R1
0.1%
VI(ref)
R2
0.1%
VO
Input
ǒ Ǔ
+ 1 ) R1
V
R2 I(ref)
NOTE A: R should provide cathode current ≥1 mA to the TL1431 at
minimum V(BATT).
Figure 16. Shunt Regulator
14
VO
Von ≈ 2 V
Voff ≈ V(BATT)
TL1431
POST OFFICE BOX 655303
TL1431
VIT = 2.5 V
GND
Figure 17. Single-Supply Comparator
With Temperature-Compensated Threshold
• DALLAS, TEXAS 75265
TL1431
PRECISION PROGRAMMABLE REFERENCE
SLVS062F – DECEMBER 1991 – REVISED JANUARY 2000
APPLICATION INFORMATION
V(BATT)
V(BATT)
R
IN
µA7805
2N2222
30 Ω
2N2222
0.01 µF
TL1431
OUT
Common
R1
TL1431
R2
4.7 kΩ
VO
R1
0.1%
R2
0.1%
VO
VO
ǒ Ǔ
V
+ 1 ) R1
R2 I(ref)
V
NOTE A: R should provide cathode current ≥1 mA to the TL1431 at
minimum V(BATT).
ǒ Ǔ
+ 1 ) R1
V
R2 I(ref)
Min V = VI(ref) + 5 V
Figure 19. Output Control of a
Three-Terminal Fixed Regulator
Figure 18. Precision High-Current Series Regulator
V(BATT)
V(BATT)
R
VO
VO
R1
TL1431
R1
C
R2
R2
VO
TL1431
ǒ Ǔ
+ 1 ) R1
V
R2 I(ref)
V trip
NOTE A: Refer to the stability boundary conditions in Figure 15 to
determine allowable values for C.
Figure 20. Higher-Current Shunt Regulator
POST OFFICE BOX 655303
ǒ Ǔ
V
+ 1 ) R1
R2 I(ref)
Figure 21. Crowbar
• DALLAS, TEXAS 75265
15
TL1431
PRECISION PROGRAMMABLE REFERENCE
SLVS062F – DECEMBER 1991 – REVISED JANUARY 2000
APPLICATION INFORMATION
V(BATT)
In
V(BATT)
VO = 5 V
Rb
Out
VO = 5 V, 1.5 A, 0.5%
LM317
27.4 kΩ
0.1%
8.2 kΩ
Adjust
TL1431
TL1431
243 Ω
0.1%
27.4 kΩ
0.1%
243 Ω
0.1%
NOTE A: Rb should provide cathode current ≥1 mA to the TL1431.
Figure 23. 5-V Precision Regulator
Figure 22. Precision 5-V, 1.5-A, 0.5% Regulator
12 V
6.8 kΩ
5 V +0.5%
VCC
10 kΩ
–
TL1431
10 kΩ
0.1%
+
X
Not
Used
10 kΩ
0.1%
TL598
Feedback
Figure 24. PWM Converter With 0.5% Reference
16
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TL1431
PRECISION PROGRAMMABLE REFERENCE
SLVS062F – DECEMBER 1991 – REVISED JANUARY 2000
APPLICATION INFORMATION
R3
V(BATT)
R1B
R1A
TL1431
12 V
2 kΩ
R
TL1431
R2A
TL1431
R2B
ǒ Ǔ
ǒ Ǔ
+ 1 ) R1B
V
R2B I(ref)
High Limit + 1 ) R1A V I(ref)
R2A
Low Limit
680 Ω
R4
On
C
Off
LED on When
Low Limit < V(BATT) < High Limit
NOTE A: Select R3 and R4 to provide the desired LED intensity and
cathode current ≥1 mA to the TL1431.
Figure 25. Voltage Monitor
RCL 0.1%
V(BATT)
Delay
+R
C
II
*
12 V
(12 V) V
I(ref)
Figure 26. Delay Timer
IO
V(BATT)
IO
R1
TL1431
TL1431
IO
+
R1
+
VI(ref)
R CL
) IKA
ǒǓ
RS
0.1%
V (BATT)
IO
hFE
) IKA
IO
Figure 27. Precision Current Limiter
POST OFFICE BOX 655303
+
VI(ref)
RS
Figure 28. Precision Constant-Current Sink
• DALLAS, TEXAS 75265
17
IMPORTANT NOTICE
Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue
any product or service without notice, and advise customers to obtain the latest version of relevant information
to verify, before placing orders, that information being relied on is current and complete. All products are sold
subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those
pertaining to warranty, patent infringement, and limitation of liability.
TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in
accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent
TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily
performed, except those mandated by government requirements.
CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF
DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL
APPLICATIONS”). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, AUTHORIZED, OR
WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT DEVICES OR SYSTEMS OR OTHER
CRITICAL APPLICATIONS. INCLUSION OF TI PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO
BE FULLY AT THE CUSTOMER’S RISK.
In order to minimize risks associated with the customer’s applications, adequate design and operating
safeguards must be provided by the customer to minimize inherent or procedural hazards.
TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent
that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other
intellectual property right of TI covering or relating to any combination, machine, or process in which such
semiconductor products or services might be or are used. TI’s publication of information regarding any third
party’s products or services does not constitute TI’s approval, warranty or endorsement thereof.
Copyright  2000, Texas Instruments Incorporated